Floyd Mayweather Pays Nicki Minaj $50K To Show Up at Daughter's B-Day

Nicki Minaj doesn't even have to sing to make bank -- sources tell TMZ Floyd Mayweather Jr. paid her $50,000 just to show her face at his daughter's 14th birthday party.According to sources, Mayweather rented out the entire MGM ballroom in Vegas to celebrate Iyanna Mayweather's birthday last weekend -- and Nicki showed up to surprise her.

We're told Nicki stayed for about an hour -- hanging out with Iyanna, taking pics ... and that's pretty much it.

You'll recall, Iyanna's birthday party is essentially what set off the brawl between T.I. and Floyd -- after T.I.'s wife Tiny posted a photo of herself with Iyanna. Tiny was an unpaid guest.

Iyanna's pretty spoiled as far as celeb guests go -- last year, Justin Bieber showed up at her party.

Just imagine what her sweet 16 will look like.